int blinkState = 0; // Condizione iniziale Low
unsigned long closedMillis = millis();
unsigned long openMillis = millis();

struct blinkStatus {
  int blinkState;
  unsigned long closedMillis;
  unsigned long openMillis;
};

void setup() {
  pinMode(13, OUTPUT);
}

void loop() {
  struct blinkStatus T7Stat = blinkModel …;
  if (millis() - closedMillis >= 1000) {
    blinkState = (blinkState == LOW) ? HIGH : LOW;
    digitalWrite(7, blinkState);
    closedMillis = millis();
  }
}